"At our manufacturing facility, we produce powdered products and often see failures with our bearings, which end up buried underneath piles of our product. In a high contamination area such as this, would you recommend something like automatic lubricators or solid lube bearings?"
Allowing dust or powder to cover a greased bearing is a situation that should be avoided if at all possible. This type of contamination will insulate the bearing and cause a buildup of heat. In many cases, these bearings are already at or near their maximum operating temperatures. Keep in mind that for every increase of 18 degrees F (10 degrees C), you effectively cut the life of your lubricant in half.
The abrasiveness of the powder being produced could also be a factor in the early demise of your bearings, as it could be acting like sandpaper on the bearing surfaces, depending on the material from which it is constructed. If the material is made up of powdered metals, such as what's used to produce sintered metal parts, it may be particularly hard and could definitely have an abrasive effect.
In addition, the powdered products could be causing a detrimental chemical reaction with the lubricant, resulting in the lubricant hardening prematurely or the oil within the grease leaching out.
The bearings' construction is another factor that can affect how well they are able to prevent contaminant ingression. Choosing the right bearings for your application will be key for their reliability. Double shielded or even sealed bearings may outlast bearings that must be greased every week, as they offer little to no chance for contaminants to enter. In this situation, solid lube bearings may be a good choice. Single-point lubricators are also an excellent option if the bearings are in an area that is difficult to access or if a constant supply of grease is required.
Other important considerations that could influence your lubricant decision would include the size and type of bearings, the speed at which the bearings work, the temperature of the bearings, the load under which the bearings are working, the ambient temperature and the type of lubricant being used.
The best advice would be to keep the area around the bearings free from the powdered product, make certain the correct lubricant is being used for the application, and ensure the bearings and lubricant are kept clean, cool and dry.